a. Field
The present disclosure relates to catheter location and imaging; and among other things, the present disclosure relates to devices, systems, and methods for locating, with six degrees of freedom, a catheter.
b. Background Art
Electrophysiology catheters are used in a variety of diagnostic and therapeutic medical procedures to correct conditions such as atrial arrhythmia, including for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter. Arrhythmia can create a variety of dangerous conditions including irregular heart rates, loss of synchronous atrioventricular contractions and stasis of blood flow which can lead to a variety of ailments or death.
In a typical procedure, a catheter and sheath are manipulated through a patient's vasculature to a patient's heart. In a conventional approach, an introducer is used to puncture the skin surface and a sheath having an inner diameter greater than the outer diameter of the catheter is threaded through the vasculature to a region of interest. The catheter is then moved longitudinally through the sheath to the region of interest either manually by a clinician or through the use of electromechanical drive systems. The catheter carries one or more electrodes which may be used for mapping, ablation, or other treatments. Once positioned, treatment may include radio frequency (RF) ablation, cryoablations, lasers, chemicals, high-intensity focused ultrasound, etc. An ablation catheter imparts energy to the cardiac tissue to create a lesion that disrupts undesirable electrical pathways, thereby limiting or preventing stray electric signals leading to arrhythmias. The position of the ablation catheter within the heart can directly affect the physician's ability to accurately and effectively perform an ablation procedure.
Two catheter based imaging modalities are commonly used in electrophysiology procedures, the first being intracardiac echocardiography (“ICE”) that produces an ultrasound or “echo” image displaying structures within an echo plane emitted from a transducer in a catheter. Traditionally, ICE catheter orientation and position are determined by a physician with reference to landmark structures visible in the echo image in conjunction with other imaging modalities such as fluoroscopy, magnetic resonance imaging (“MRI”), or computed tomography (“CT”) models.